Information handling system port power management and cable detect

ABSTRACT

An information handling system allocates power for internal use and to support peripheral device operations by managing bi-directional power transfer at plural cable ports. A motion detector disposed in a port detects motion of a cable disconnecting from the port and communicates the motion to a power controller that coordinates termination of power draw from the cable before the power connection between the cable and port is lost.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates in general to the field of informationhandling system cabled connections, and more particularly to informationhandling system multiport power management.

Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Information handling systems continue to shrink in size and grow incapabilities. Improvements in processing capabilities have allowedinformation handling system manufacturers to pack increased processingcapability into housings of decreased size while increasing battery lifewith power savings measures. In particular, many end users appreciateinformation handling systems that have thin housings for ease ofmobility and that have power savings logic and large batteries forincreased operating times when external power is not available.

One difficulty faced by information handling system manufacturers whendesigning low-profile portable systems is providing the amount of powerthat processing components need when operating at full capacity. Often,portable information handling systems include powerful components thatwill draw current at rates in excess of the rates that an external powersupply can provide. Power saving logic drives down current draw duringidle operations, however, initiation of an application or hardwareoperation tends to spike power consumption and thus current draw inlarge variances that can occur unexpectedly. As one example, many tabletinformation handling systems powered by USB adapters cannot power upthrough a boot sequence without a battery charge to supplement externalpower.

Thin housings used for low-profile information handling systems presentseveral difficulties for power solutions acceptable to the large powerconsumption variance that can occur. One difficulty is that power andcommunication connectors located along the housing edge have minimalspace. In small tablet configurations, a single USB connector issometimes used for both power can communication. Larger tabletconfigurations and clamshell/convertible configurations tend to haveadditional cable connections, such as a dedicated power connector anddisplay connector as well as multiple USB and other data connectors;however, the housing edge space comes at a premium in thin solutions dueto structural and electrical considerations. Even where a dedicatedpower connector is included, the space available for power management,such as capacitors to manage power surges, is minimal, as is the spaceavailable for a battery.

One recent trend that aids power management is the use of variousperipheral ports to both send information and generous amounts of power.USB Type C connectors and ports, for example, may provide as much as 100W of power. DisplayPort connectors and ports using a USB type ofinterface support similar power transfer amounts. In addition, powertransfer is bi-directional so that an information handling system canprovide power to peripheral devices or can receive power when interfacedwith a device capable of providing power. However, since many ports havesimilar footprints designed to take minimal housing space, end usersface some confusion regarding which port is appropriate for which cable.Further, an end user may not understand that a peripheral port isproviding power to an information handling system or, in some cases,which peripheral port is providing power, so that the end user willexpect similar performance at an information handling system as cablesare inserted and removed. In fact, the availability of external powercan impact the capability of processing components to operate at fullcapacity. Further, connecting and disconnecting external power in anunexpected manner can introduce unpredictable power surges that lead tosystem crashes or component failures.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for a system and method which providespower to an information handling system in a flexible manner.

In accordance with the present invention, a system and method areprovided which substantially reduce the disadvantages and problemsassociated with previous methods and systems for powering an informationhandling system. A power manager monitors power sources coupled to dataand power ports of an information handling system to selectively acceptpower simultaneously from plural power sources. Available power stateconfigurations are tracked and presented to an end user with a userinterface that optimizes power transfer at the information handlingsystem for a given operating condition, such as based on available powersources, battery charge, system power consumption states, data transferneeds, etc. . . . Power and data ports are monitored for cable motion sothat changes in power state are anticipated and adapted to at theinformation handling system without disrupting system operation.

More specifically, an information handling system processes informationwith a processor and memory disposed in a housing. The housing hasplural ports that accept power cables and data cables, such as USB TypeC connectors and DisplayPort connectors. An embedded controller runningpower manager firmware code stored in flash memory manages power at theinformation handling system, including accepting power from externalsources at a charger to apply the power to run components and charge abattery. The power manager reports available power to a user interfaceat an operating system level so that an end user is presented withavailable power states based upon the power capabilities of externaldevices, such power adapters and peripheral devices configured toprovide power to the information handling system through USB Type Ccables and ports. The power manager configures multiple power sources tomatch power impedance so that the multiple sources are able tosimultaneously provide power to the information handling system. Cableports are monitored for motion of a cable that indicates a power sourcemay be disconnected so that the power manager can adapt the system tochanges in the power source configuration before the change occurs. Inone embodiment, a power cable is connected with magnetic pogo pins thatare reversibly connectable. A center pin provides ground and two outerpins provide communication and power so that the power manager detectsthe outer pin function before configuring the power source for powertransfer using the communication pin.

The present invention provides a number of important technicaladvantages. One example of an important technical advantage is that anend user is provided with a user interface that allows the end user tounderstand and manage power application from multiple external devicesso that the end user can select optimal power and data transferconfigurations. Multiple power sources couple to an information handlingsystem provide power simultaneously to improve power efficiency andensure that full power is available to the information handling systemwhen any one power source is not sufficient to meet the informationhandling system's power needs. Active monitoring of cable connections atthe information handling system provide a transition time between acable disconnect and power loss so that the information handling systemreconfigures to new power source configurations before existing powersupply is lost from a disconnecting source. In one embodiment, areversible magnetic power connector provides power and communication forcoordinating power transfer through three pin connector having theground pin in a center location.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousobjects, features and advantages made apparent to those skilled in theart by referencing the accompanying drawings. The use of the samereference number throughout the several figures designates a like orsimilar element.

FIG. 1 depicts a portable information handling system interfaced withplural peripheral devices that provide power;

FIG. 2 depicts a block diagram of an information handling systemconfigured to manage application of power from plural power sources;

FIG. 3 depicts a user interface presented at an information handlingsystem that aids end user configuration of external device connectionsto enhance power transfer from multiple external sources;

FIG. 4 depicts a flow diagram of a process for presenting end user cableconfigurations that enhance power transfer;

FIG. 5 depicts a block diagram of an information handling systemconfigured to adapt plural external power source impedances to maintaina common system droop;

FIG. 6 depicts a flow diagram of a process to adapt plural externalpower source impedances to maintain a common system droop;

FIGS. 7A, 7B and 7C depict a data connector and port having a motiondetector to provide a transition time for power transferreconfiguration;

FIGS. 8A and 8B depict current levels at power source transition withand without the power transition time;

FIG. 9 depicts a three pin reversible magnetic connector that couples toa power source;

FIGS. 10A and 10B depict a circuit diagram of one example of a powercontroller that accepts power from a reversible power connector;

FIG. 11 depicts a flow diagram of one example of a process for managingpower provided at a reversible power connector;

FIGS. 12A and 12B depict a circuit diagram of another example of a powercontroller that accepts power from a reversible power connector; and

FIG. 13 depicts a flow diagram of another example of a process formanaging power provided at a reversible power connector.

DETAILED DESCRIPTION

An information handling system accepts power from multiple powersources, including peripheral devices, by intelligently managing powertransfer between the multiple power sources. For purposes of thisdisclosure, an information handling system may include anyinstrumentality or aggregate of instrumentalities operable to compute,classify, process, transmit, receive, retrieve, originate, switch,store, display, manifest, detect, record, reproduce, handle, or utilizeany form of information, intelligence, or data for business, scientific,control, or other purposes. For example, an information handling systemmay be a personal computer, a network storage device, or any othersuitable device and may vary in size, shape, performance, functionality,and price. The information handling system may include random accessmemory (RAM), one or more processing resources such as a centralprocessing unit (CPU) or hardware or software control logic, ROM, and/orother types of nonvolatile memory. Additional components of theinformation handling system may include one or more disk drives, one ormore network ports for communicating with external devices as well asvarious input and output (I/O) devices, such as a keyboard, a mouse, anda video display. The information handling system may also include one ormore buses operable to transmit communications between the varioushardware components.

Referring now to FIG. 1, a portable information handling system 10 isdepicted interfaced with plural peripheral devices that provide power.In the example embodiment, portable information handling system 10 has aconvertible configuration with housing 12 having a keyboard 14integrated in a main portion and a display 16 integrated in a lidportion rotationally coupled to the main portion. For instance, portableinformation handling system converts between closed, clamshell open andtablet configurations. In alternative embodiments, alternative housingconfigurations may be supported, such as tablet configurations anddesktop configurations. Information handling system 10 obtains power torun components and charge an integrated battery through data ports thatthat communicate information and also include power transfer wires, suchas a USB data port 18 and a graphics data port 20. For example, a Type CUSB 18 port accepts USB cables 26 from a peripheral display device 22, aprinter 24 or other types of peripheral devices that have bi-directionalpower transfer to both receive power from information handling system 10and provide power to information handling system 10. As another example,a DisplayPort port 20 accepts a DisplayPort cable 28 from peripheraldisplay device 22 to both receive power and transfer graphics data frominformation handling system 10 to display 22. In addition to receivingpower from peripheral devices, information handling system 10 has apower connector port 30 that accepts power from an AC-to-DC adapter.

In operation, information handling system 10 configures to receive andprovide power with external devices based upon communications with eachexternal device. Power connector port 30 includes a Type C CC or vendorspecific PSID communication with AC-to-DC adapter 32 that exchangespower characteristics so that information handling system 10 draws anappropriate current without overloading adapter 32. Serial data ports 18and graphics ports 20 include dedicated data lines defined by acommunications protocol, such USB 3 or DisplayPort protocols, which alsodefines power transfer handshakes. For example, each peripheral includesa power source 34 that provides power locally to run the peripheral,such as from an external power source 38 or from power provided byinformation handling system 10 through data cable. In addition, in someinstances power sources 34 may provide power to information handlingsystem 10 through the data cable. The capability of each peripheraldevice is communicated with power characteristics through the datacable, such as with the USB or DisplayPort protocols. Informationhanding system 10 receives and sends power between each external devicebased upon the communicated capabilities and configuration of eachexternal device. For example, information handling system 10 may takepower from some peripheral devices while providing power to run otherperipheral devices based upon the capability of an external poweradapter 32.

Referring now to FIG. 2, a block diagram depicts an information handlingsystem 10 configured to manage application of power from plural powersources. A hardware layer includes processing resources to store andexecute instructions. For example a central processing unit (CPU) 38executes instructions in combination with a random access memory (RAM)40. A chipset 42 includes processing resources and flash memory thatexecute firmware instructions. For instance, an embedded controller 44manages communication with power resources and input/output devices. Agraphics controller 46 manages communication with integrated andexternal graphics devices, such as by generating pixel values forpresentation of visual images at a display communicated through graphicsport 20. Embedded controller 44 interfaces with a USB hub 48 or othertype of serial port hub to manage communication of data and power at USBport 18. Movement of cables into and out of ports 18 and 20 is monitoredby a motion detector 50, as set forth in greater detail below. A charger54 adapts power for specific uses, such as charging a battery orpowering various busses with various voltage and current levels.

The hardware layer is managed at a physical level by instructions storedin persistent memory as firmware in a firmware layer. Generally,physical component interactions are managed by a Basic Input/OutputSystem (BIOS) or similar device running on embedded controller 44 and/orrelated microprocessors. For example, BIOS 56 includes modules thatmanage power, such as a power manager 58 and a port power engine 60,both described in greater detail below. BIOS 56 interacts with anoperating system layer to provide information to and accept inputs froman end user. For example, a port power user interface 62 presents to theend user the available power transfer states 64 so the end user mayselect cable and port connections that provide optimal power transferconfigurations for the end user. As an example, port power engine 60detects connections for USB ports 18 and graphics ports 20 withperipheral devices and analyzes the power capabilities of eachperipheral device to suggest the port and cable connections that willprovide the most rapid battery charge. If, for instance, an end userplugged a USB Type C display into a port that is not DisplayPort ALTmode capable, the end user is provided with a graphical suggestion of aport location on the information handling system that will provide powertransfer with the Type C display. In one example embodiment, the enduser is presented with a user interface that depicts variouscombinations of port connections and the power transfer state of eachcombination. Port power engine 60 monitors all port plug status changesand port instantaneous power draws to maintain a port status tablereferenced by port power user interface 62. Port power engine 60 managespower transfer at the plural ports based upon detected port cableconnections, detected power source and detected power transferconfigurations, including peripheral devices that source and/or sinkpower. By tracking total instantaneous port power allocation and systempower budgets, port power engine 60 dynamically adjusts system resourcesbased on the system and plugged device power status changes to directthe user through power user interface 62 of an appropriate match ofperipheral capabilities to port capabilities. This active monitoringhelps to ensure that peripheral devices that draw power will also haveadequate power through available port resources, such as when aperipheral device that was providing power transitions to receivingpower from the information handling system. As an example, when onbattery power, port power engine may suggest use of a display havingless power consumption to present information; on the other hand, if thedisplays have external power to provide to the information handlingsystem, port power engine may suggest power be provided from the displayhaving the greatest power transfer rate. In one embodiment, otherfactors may be considered, such as video quality when visual images arepresented by streaming using battery versus external power.

Referring now to FIG. 3, a user interface 64 presented at an informationhandling system 10 is depicted that aids end user configuration ofexternal device connections to enhance power transfer from multipleexternal sources. Information handling system 10 detects all cablesconnected to ports, the presence/absence of an external power adapter32, a battery charge state and data transfer configurations, and thenpresents available power transfer states at user interface 64, such aspower states available to accept external power and to power externaldevices. In the example embodiment, an end user is informed that adisplay coupled to a port is not currently providing power and ispointed to a different port that the end user can use that will providepower transfer from the display to the information handling system. Userinterface 65 depicts different power transfer states based upon poweruse and need, and also based upon data use and need. For example, adocking station provides an interface with a display 22 and powerthrough a USB Type C cable. If information handling system 10 has a lowbattery charge and display 22 provides power, user interface 64 presentsthe option of directly coupling display 22 to a DisplayPort port ofinformation handling system 10 to increase charge rate by acceptingpower from both display 22 and the docking station. If printer 26 doesnot provide power through its cable, user interface 64 suggestsinterfacing printer 26 through the docking station to open up a port fora direct connection by display 22 that can provide power. If, on theother hand, information handling system 10 has a full battery charge andpower provided by the docking station is adequate for running processingcomponents, user interface 64 will not disrupt the end user with otherpower and data cable configurations. Other situations that may ariseinclude power transfer from information handling system 10 to aperipheral, such as display 22, where the display does not have its ownpower source. For example, user interface 64 may suggest unplugging adisplay 22 that draws power during battery charge so that the full powercapability of the system is available to charge the battery instead ofrunning peripheral devices. In such an example situation, user interface64 will suggest swapping a display 22 that provides power and isconnected to a docking station with a display 22 interfaced directly toan information handling system port that does not provide power or drawspower. As another example, where power into an information handlingsystem can be supplemented by a fully-charged battery as needed, a lowerpower-in state may be suggested for a configuration that will provide agreater data transfer, such as where a user is streaming a move.

Referring now to FIG. 4, a flow diagram depicts a process for presentingend user cable configurations that enhance power transfer. At step 70,connections at each port are queried for power configuration parametersand each port is configured to accept or provide power as appropriate.In various embodiments, two or more ports may simultaneously receivepower from external devices, such as a power adapter or a peripheral. Atstep 72, the ports are monitored to detect any change is portconnections, and if no change is detected the process returns to step70. If a change in port configuration is detected at step 72, theprocess continues to step 74 to compare the configured power into theinformation handling system with the available power from the newlydetected port configuration. At step 76 a determination is made ofwhether a configuration is available with more power available to theinformation handling system than in the present configuration. If notthe process continues to step 70. If a configuration with more powertransfer is available, the process continues to step 78 to suggest amodified cable configuration to the end user through the power stateuser interface.

Referring now to FIG. 5, a block diagram depicts an information handlingsystem 10 configured to adapt plural external power source impedances tomaintain a common system droop. Information handling system 10 has apower controller 44, such as embedded controller, that manages systempower through a charger, such as by outputting power to one or moresystem busses sourced from external power or a battery. For example, apower manager 58 includes local power characteristics 36 that the powercontroller communicates with external power sources to manage powertransfer. Power manager 58 coordinates with multiple external powersources to accept power from plural sources simultaneously, such as fromone or more power adapters and/or one or more peripheral devices 80. Inthe example embodiment, each of plural peripheral devices 80 includes apower manager 58 and locally stored power characteristics that arecommunicated with information handling system 10. By tracking powercharacteristics 36 of each external device coupled to it, each powermanager 58 adjusts power output characteristics to provide power at alevel that works with other devices simultaneously transferring power.For instance, in some example embodiments power is provided to aninformation handling system simultaneously through plural USB Type Cports, plural DisplayPort graphics ports, various combinations of USBdata ports, graphics ports and power adapter ports that are included totransfer power without data (other than power source identification andcharacteristics).

In one example, power manager 58 of information handling system 10identifies with USB and DisplayPort power handshakes the output ratingof each attached peripheral device using digital communication lines.For peripheral devices that have compatible power transfer capabilities,the power manager 58 commands an output impedance that each peripheraldevice 80 configures itself to output so that the power output of eachperipheral device matches during changes of current draw by informationhandling system 10. In one example embodiment, the power manager 58 ofinformation handling system 10 retrieves the current rating of eachperipheral device 80 and applies the information handling system voltagedroop to determine a peripheral device impedance setting according tothe formula:

${Rout}_{imp} = \frac{V_{droop}}{{Isource}_{rating}}$

-   -   Where;        -   Rout_(imp) Adapter output impedance.        -   Vsys_(droop) System Droop allowed from nominal.        -   Isource_(rating) Source power rating.

Alternatively, power manager 58 communicates a voltage droop setting toeach power-capable device 80 so that each device 80 sets an outputimpedance that will match that provided from information handling system10. The programmed output impedance will be system dependent andinversely proportional to the current rating of each peripheral device80. For example, with two peripheral devices 80 coupled to informationhandling system 10 having a system output voltage droop of 200 mV overthe system demand, a source rated at 2.5 A and a source rated at 4.5 Awould set their output impedance at 80 mOhms and 40 mOhms respectfully.In the event that the output impedance is determined at the peripheraldevice 80, information handling system 10 provides the voltage droop sothat the peripheral device may compute the output. Advantageously,providing power from multiple external sources allows informationhandling system 10 to draw its maximum rated power where drawing currentfrom just one external device would not provide maximum rated current.With matched impedance, all power sources will provide proportionalpower relative to the maximum power available. Power manager 58 canselectively adapt to receive power from just one device as desiredduring times of low power draw so that extra charger devices ofperipheral devices may enter a power saving state. End users will nothave an impact with reduced performance since a battery can supplementcurrent draw until a second power source is returned to an active state.Operating power sources at moderate levels of current production helpsto increase power transfer efficiency, which may be coordinated throughtransfer of power efficiency factors with the power characteristics 36.

Referring now to FIG. 6, a flow diagram depicts a process to adaptplural external power source impedances to maintain a common systemdroop. At step 82 a new power source is detected at a device port, suchas a power port that couples to a power adapter or a data port thatcouples to a data cable. At step 84 a determination is made of whetherthe new power source is the only available power source or one ofmultiple power sources. In one example embodiment, a power source may beconsidered as the only power source if the power source has adequatecurrent to meet the maximum current draw of the information handlingsystem. If the power source is the only power source, the processcontinues to step 86 for the system controller, such as a power mangerrunning on an embedded controller, to detect and negotiate power sourcecapabilities through a control interface, such as USB, DisplayPort, orPSID interfaces. If at step 84 the new power source is not the onlypower source, the process continues to step 88 for the system controllerto identify each attached power source and confirm that the powersources are compatible with a multi-power source load contribution. If apower source is not capable of configuring for multiple power sourcesharing, then the source may be treated as the only source or turned offto prevent power contribution and the process continues to step 86 toconfigure power sources accordingly.

Once all power sources are identified that are compatible with powersharing, the process continues to step 90 to configure the power sourcesfor power sharing. The system controller communicates the system powerprofile to each of the power sources, such as the allowed voltage droopat the system and the maximum current available from each power source.In response to the system power profile information, the informationhandling system and power sources set their power characteristics todesired settings. For example, based upon the voltage droop providedfrom the information handling system, each power source sets a matchingpower impedance to allow each power source to contribute to system powerproportional to their output rating. At step 92, the status of the powersources is changed to reflect the updated impedance settings and theprocess returns to step 82 to monitor a change in status of powersources. If at step 92 the power sources do not match or successfullyconfigure to share power contribution, the process returns to step 90 toreattempt configuration.

Referring now to FIGS. 7A, 7B and 7C, a data connector 94 and port 18are depicted having a motion detector 50 to provide a transition timefor power transfer reconfiguration. As presented in FIG. 7A, on fullinsertion of cable plug 94 into port 18, motion detector 50 is pressedbackwards to provide a Vdetect signal that indicates full insertion ofcable plug 94 into port 18. At full insertion, power lines 102 in port18 receive power from power lines of cable plug 94 so that power isprovided to an information handling system charger coupled to port 18.As presented in FIG. 7B, on initiation of withdrawal of cable plug 94from port 18 motion detector 50 closes a switch that indicates awithdrawing motion has begun before power is removed from power lines100 of port 18 since a power connection remains for at least part of thewithdrawing motion as power lines of cable plug 94 remain in contactwith power lines 100 in port 18. FIG. 7C illustrates that a transitiontime 102 is provided between the change in value of Vdetect and thechange in power applied by cable plug 94 at Vbus. In a multi-plug powersituation as described above with respect to FIG. 6, transition time 102provides adequate warning to the power manager of a change in availableexternal power so the power manager can reconfigure power into theinformation handling system before the available power in changes.Although FIG. 7 depicts a motion detector 50 in the form or a switchthat is triggered by full or partial insertion of a plug, in alternativeembodiments other types of motion detectors may be used, such as aninfrared sensor that monitors plug 94 or a Hall sensor that usesmagnetic interactions to detect motion or full insertion of plug.

Referring now to FIGS. 8A and 8B, current levels at power sourcetransition are depicted with and without the power transition time.Information handling system 10 has an allowed voltage droop that defineshow much voltage is allowed to drop when current draw increases. In theevent of an unplugging motion of a power source in a multi-power sourceconfiguration, voltage droop is expected when power ceases from theunplugged power source and until the power manager and remaining powersource are able to re-establish the designed Vbus. System voltage isre-established by a combination of reducing current draw by theinformation handling system from the remaining power source anddecreasing impedance of the remaining power source so that its currentoutput increases. In order to absorb some of the increase current demandfrom the remaining power source during a transition time, capacitancemay be added to the information handling system, however, suchcapacitance comes at a cost in both components and board space.

FIG. 8A depicts the increase in current draw and droop in voltage thatcan occur in one example embodiment at the unplugging of a power sourcewithout prior notice. Vbus drops at the unplug event to a Vth level thattriggers a detection of a power source change. In response to thevoltage droop caused by the primary Vbus unplug event, adapter currentto supply power at a secondary Vbus spikes to a high current value inattempt to raise the system voltage to a target value. The ramp incurrent increase from the remaining power source stresses current outputcapacity and takes a ramp up time that can respond to slowly to maintainvoltage at a level adequate to keep the information handling systemrunning. In contrast, FIG. 8B depicts voltage and current response wherea motion detector provides warning of an unplug event before power iscut off due to the unplug event. Upon motion detection at a port plug,the power manager responds by preparing the information handling systemto run without power provided by the port. The transition may involve avariety of steps that will reduce the impact of a sudden loss of currentfrom the port. For example, the power manager reconfigures the powertransfer impedance for the two power sources to have power provided onlyby the power source that does not have motion detected. As anotherexample, power provided from an integrated battery may supplementcurrent before a disconnect of the cable from the port where motion isdetected. Other examples may include reconfiguring of the informationhandling system to receive power from other cables and ports that havepower transfer capability that is not in use. In each instance, thepower transition warning provided by motion detection of a cable at apower-providing port gives the power manager time to initiate atransition to removal of the power source before the power source islost so that the voltage droop and related current inrush are minimized.In FIG. 8B, the example embodiment initiates a power current increaseavailable from the secondary power source before the primary powersource is removed.

Referring now to FIG. 9, a three pin reversible magnetic connector 106is depicted that couples to a power source. In the example embodiment, apower adapter 32 provides current through a power cable 104 to powerconnector 106 with three power pins disposed in a linear arrangement.Power pins 108 align with power connector pins 110 in a reversiblemanner. In the example embodiment, power pins 108 and power connectorpins 110 couple together and are held together with magnetic attraction,such as by having a magnet and/or ferromagnetic material disposed in thehousing of information handling system 10 and magnetic connector 106. Inone embodiment, the pins include a spring bias that detects a separatingmotion of a cable from a housing to provide warning of a changed powerconfiguration as set forth above with respect to motion detection.

Referring now to FIG. 10, a circuit diagram depicts one example of apower controller that accepts power from a reversible power connector.Power cable connector 106 has three pins disposed in a linearconfiguration and having a ground pin in the center location with powerand communication pins located at end positions. The housing powerconnector 110 also has three pins in a linear arrangement, however, thepower and communication pin locations on opposing ends of the lineararrangement are configurable depending upon the orientation of powercable 106. Power controller circuit 112 detects the orientation of powercable 106 relative to power connector 110 and configures the outer twopins to accept power or communication based upon a determination of thepower cable pin that has contacted it. In other words, the housing powerconnector outer pins adapt by automated configuration to perform eithercurrent of information transfer based upon the orientation at which thepower cable couples to the housing.

When power adapter 32 pins 108 contact information handling system pins110, ground is known since ground is located in a middle position, butpower and communication pins may align on either side of informationhandling system 10 based upon power cable orientation. Power controllercircuit 112 determines which outer pin 110 has connected to power andwhich has connected to communication, and then configures itself toaccept power and communications accordingly. In at idle state awaiting apower cable connection, Q8 is self-biased ON by Vrp provided at thepower V+ and communication CC nodes. At connection of a power cableconnector pins 108 to pins 110, the external adapter detects Rd and inresponse outputs 5V at Vbus for the V+ pin and broadcasts power sourcecapability through the CC pin. The 5V of power travels via Q2 to a lowdrop out regulator (LDO) 114 that outputs Vcc_ec to power embeddedcontroller 44 to execute a power manager that manages power input athousing power connector 110.

Once embedded controller 44 is powered by LDO 114, a power managerstored in flash memory executes to boot the embedded controller in apre-BIOS mode that allows determination of the orientation of powercable 106 relative to power connector 110. In the example embodiment,embedded controller 44 reads the value of pin FWD_EN and optionallyREV_EN to set the pins 110 for power or communication inputs. After theembedded controller negotiates power transfer characteristics, using thecommunications line CC, power transfer ramps up on the power line untilVbus_in exceeds the set ACOK limit, at which time embedded controller 44enables Q2 to set the input current line to charger 54. In this manner,higher current levels are passed to charger 54 after the power-in lineis identified.

Referring now to FIG. 11, a flow diagram depicts one example of aprocess for managing power provided at a reversible power connector. Theprocess starts at step 116 with attachment of an external power sourceto a housing connector. At step 118, the external power source detectsthe connection Rd and in response enables voltage at Vbus to outputvoltage from the power sources to the housing connector. At step 120,the voltage from Vbus enters the connector with adequate current poweran LDO with a minimal output to an embedded controller, such as 15 mA.At step 122, power provided from the LDO boots the embedded controllerto a pre-BIOS operational state. The LDO powers the embedded controllerwith Vbus provided at either of the outside connection pins. At step124, the embedded controller analyzes the power in to determine whichhousing connector pin is receiving the power by determining whichconnector pin has a higher voltage state. If the Vbus1 has a lowervoltage, the process continues to step 126 to enable bus line 1 as thecommunication link. If Vbus1 has a higher voltage, the process continuesto step 128 to enable bus line 2 as the communication link. At step 130,the charger in the information handling system initiates a powerhandshake through the communication line to negotiate a power exchangecontract. At step 132, the external power source initiates powertransfer at the negotiated contract. At step 134, the charger providesthe negotiated power transfer contract information to the embeddedcontroller and, at step 136, the embedded controller sets the powertransfer based upon system need. The process ends at step 138 with theinformation handling system and external power source configured toexchange power with correctly configured power and communication lines.

Referring now to FIG. 12, a circuit diagram depicts another example of apower controller that accepts power from a reversible power connector.In the example embodiment of FIG. 12, a manufacturer specific powersystem identifier (PSID) is communicated to provide external powersource characteristics instead of standardized CC power communications.Embedded controller first attempts communication with a standardized CCprotocol and, if communication is not found, determines that theconnector is not a Type C USB connector. In response, embeddedcontroller 44 initiates alternative power protocol communications usingvendor specific and/or USB 2 communication protocols to establish powertransfer. A soft start FET 140 is disposed on the communication andpower lines to prevent arching or other damage in the event of a currentin rush from a 20V power source. In addition, if an external poweradapter is detected but Rd is not detected, embedded controller 44checks an AC_OK signal to determine the proper type of protocol ID, suchas a vendor specific PSID or a microUSB 2.0 connector. For example, if a5V input is detected without a Type C Rd indication, a microUSB isdetermined; and if a voltage of greater than 5V is detected without aType C Rd indication, a vendor specific power source is determined.

Referring now to FIG. 13, a flow diagram depicts another example of aprocess for managing power provided at a reversible power connector. Theprocess starts at step 142 with connection of an external power source,provides power through an LDO to the embedded controller at step 144,and initiates pre-BIOS logic of the embedded controller at step 146. Atstep 148, the line that accepts the 5V is identified so that theappropriate communication line is configured at either step 150 or 152.At step 154, the charger starts Type C CC logic to identify the powersource and negotiate the power transfer. At step 156, failure of powersource identification is detected, for example by a lack of response toa CC protocol message. At step 158, the embedded controller initiatespower handshakes by alternative protocols, such as USB 2 protocols ormanufacturer specific PSID protocols. At step 160, embedded controller44 sets an appropriate power configuration based upon successfulcommunications with an alternative protocol and, at step 162 the processends.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

What is claimed is:
 1. An information handling system comprising: ahousing; a processor disposed in the housing and operable to executeinstructions to process information; a memory disposed in the housingand interfaced with the processor, the memory operable to store theinformation; at least one communication port disposed in the housing,the at least one communication port operable to accept a cableconfigured for a communication protocol having power transfer throughthe cable; a power connector disposed in the housing and operable toaccept a power cable that provides power from an external power supply;a power controller interfaced with the at least one communication portand the power connector to accept power for application to the processorand memory, the power controller simultaneously accepting power fromboth the communication port and the power connector; and a motiondetector interfaced with the power controller and operable to detectmotion of a cable in the communication port, the motion detectorcommunicating detected motion to the power controller; wherein the powercontroller in response to detected motion manages current droopassociated with power supplied at the power connector by adapting tosupply power with reduced impedance from only the power connectorwithout power from the communication port before loss of power from thecommunication port.
 2. The information handling system of claim 1wherein the motion detector comprises a switch activated by insertion ofthe cable into the port, the switch detecting withdrawal of the cablefrom the port before a power line of the cable disconnects from a powerline of the port.
 3. The information handling system of claim 1 whereinthe communication port comprises a USB port.
 4. The information handlingsystem of claim 1 wherein the communication port comprises a graphicsport.
 5. The information handling system of claim 1 wherein the powercontroller adapts to supply power without power from the communicationport by commanding a decrease in power draw through the communicationport before loss of power from the communication port.
 6. Theinformation handling system of claim 1 wherein the power controlleradapts to supply power without power from the communication port bytemporarily supplementing current from an integrated battery before lossof power from the communication port and reducing current from theintegrated battery after loss of power from the communication port. 7.The information handling system of claim 1 wherein the power controlleradapts to supply power without power from the communication port byincreasing current from a second communication port.
 8. The informationhandling system of claim 1 wherein the power controller adapts to supplypower without power from the communication port by increasing currentfrom the power connector.
 9. A method for managing power at aninformation handling system, the method comprising: powering theinformation handling system simultaneously with first and secondexternal power sources through first and second cables connected atfirst and second ports, at least one port comprising a data cable port;monitoring the first and second ports to detect a withdrawing motion ofthe cables from the ports; detecting a withdrawing motion of the firstcable from the first port; and in response to the detecting, adaptingthe powering to manage current droop at powering with only the secondcable before the withdrawing removes power provided by the first cable,the adapting including at least reducing current draw by the informationhandling system before the withdrawing removes power provided by thefirst cable.
 10. The method of claim 9 wherein the detecting awithdrawing further comprises moving a spring contact of the port tosignal the withdrawing before a power line of the cable disengages apower connector of the port.
 11. The method of claim 9 wherein thedetecting the withdrawing further comprises detecting motion of thecable relative to the port with an infrared sensor.
 12. The method ofclaim 9 wherein the detecting the withdrawing further comprisesdetecting motion of the cable relative to the port with a Hall sensor.13. The method of claim 9 wherein both the first and second portscomprise data cable ports that interface with peripheral devices throughdata cables.
 14. The method of claim 13 wherein powering the informationhandling system further comprises combining power from the first andsecond ports at a power controller, the power controller drawing apredetermined maximum current, the first and second ports providing lessthan the predetermined maximum current individually and greater than thepredetermined current cumulatively.
 15. A cable port comprising: ahousing configured to accept a data cable; plural data lines disposed inthe housing and aligned to interface with data lines of the data cable;one or more power lines disposed in the housing and aligned to interfacewith one or more power lines of the data cable; a motion detectordisposed proximate the housing and oriented to detect movement of thedata cable; and a power controller interfaced with the motion detector,the power controller operable to simultaneously draw power from both apower port and one or more of the plural data cable power lines, thepower controller managing current droop associated with removal of adata cable detected by the motion detector by transitioning to drawpower from only the power port and disabling power draw from the one ormore data cable power lines before movement of the data cabledisconnects the one or more power lines.
 16. The cable port of claim 15wherein the motion detector comprises a contact switch engaged by thedata cable insertion into the housing.
 17. The cable port of claim 15wherein the housing has a USB Type C form factor.
 18. The cable port ofclaim 15 wherein the housing comprises a graphics cable connector formfactor.
 19. The cable port of claim 15 wherein the power controller isfurther operable to coordinate bi-directional power transfer through theone or more power lines.
 20. The cable port of claim 15 wherein thepower controller supplements power with a battery before the data cabledisconnects power from the port.